What is LightFrame Technology?

CRT monitors and TVs have each been optimised for the applications they’ve been traditionally used for. The former excel at displaying close-up high-resolution content, such as text, while lower-resolution TV screens’ larger dot pitch and higher light output make them more suitable for rendering low-resolution photography such as film, intended for viewing at a distance.

TVs can use an extremely high beam current to produce vivid images, and take advantage of a phenomenon called pixel blooming, in which adjacent pixels illuminate one another, thereby achieving a higher level of brightness. Another TV technique is peaking, which artificially sharpens a video signal’s light/dark transitions.

The problem is that neither of these techniques is appropriate on high-resolution PC monitors, as they would result in a performance degradation in traditional computer applications – such as word processing and spreadsheets. Consequently, PC users have had to live with TV-quality applications often appearing flat, dull and lifeless when displayed on a CRT monitor. Of course, the rise of home video editing, DVD playback on the desktop and even video content on the Web means this deficiency has become increasingly unacceptable.

Philips’ answer to the problem came in the shape of their unique and innovative LightFrame technology, first revealed in late 2000. In essence, LightFrame seeks to simulate the output performance of a TV screen on a PC monitor, theoretically delivering the best of both worlds.

It comprises a software application and an integrated circuit embedded in a monitor which work together to selectively raise brightness and sharpness. The software transmits co-ordinates of the selected screen area to the monitor by writing instructions on the last line of the video signal. These are translated by a proprietary integrated circuit in the monitor to boost sharpness and brightness in the selected area before being blanked out. Non-selected portions of the screen are unaffected by the process.

Extensive testing has confirmed that LightFrame does not adversely effect monitor life. Modern-day monitors have improved phosphors, designed for high light output. Though the peak brightness of a highlighted area is strongly increased, the average brightness – a determining factor for cathode deterioration – is not normally increased. In any case, LightFrame employs a special Automatic Beam Limited (ABL) circuit to keep a monitor’s maximum average brightness within acceptable levels.

A year after the technology was first introduced, LightFrame 2 was launched, offering automatic detection and enhancement of applications that benefit from the technology. This was followed in the summer of 2002 by the announcement of LightFrame 3, boasting the ability to automatically enhance up to 16 images simultaneously in Microsoft’s Internet Explorer and up to 8 when using photo-viewing applications. Interestingly, Philips intend to migrate LightFrame 3 to its LCD monitors too.

LightFrame works by identifying a rectangular screen area for highlighting. On occasions, certain backgrounds or borders prevent a photo or video from being detected automatically. In such cases it’s necessary to highlight it manually. This is accomplished by dragging a rectangle to encompass the selected area, or, to select an entire window, by a single click of the mouse.